UPSTREAM: sched/fair: Change 'prefer_sibling' type to bool

This variable is entirely local to update_sd_lb_stats, so we can
safely change its type and slightly clean up its initialisation.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: gaku.inami.xh@renesas.com
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1530699470-29808-7-git-send-email-morten.rasmussen@arm.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit dbbad719449e06d73db21598d6eee178f7a54b3b)
Signed-off-by: Quentin Perret <quentin.perret@arm.com>

Change-Id: Ida430fc3f4c5acbc996da93f886b821d488281e2